Coded train control system for railroads



June 13, 1939.

W. H. REICHARD CODED TRAIN CONTROL SYSTEM FOR RAILROADS Filed NOV. 27, 1956 s. in? m i Patented June 13,- 1939 PATENT OFFICE CODED TRAIN CONTROL SYSTEM- FOR. RAILROADS Wade H. Reichard, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application November 27, 1936, Serial No. 112,856

4 Claims.

This invention relates in general to train control systems of the coded inductive type and more particularly refers to a system for controlling the forward and reverse movements of trains in terminals or in interlocking plants.

In making switching moves it is very often desirable that the engineer of a train be informed immediately when the rear end of the train has cleared a switch and also to be advised when the route has been set up for a reverse move over the switch. In many instances the engineer cannot see for himself when his train has cleared the switch, and indications normally given to convey such information are invisible from the front end of a train due to the distance from the switch or to an obstruction blocking the View;

With the above and other considerations in mind it is proposed in accordance with this invention to provide means for communicating the aforementioned information to the moving vehicle, such information to be in addition and supplementing the usual wayside signals.

This invention contemplates a cab signal system responsive to coded current impressed on an insulated code wire located between the rails of the section of trackway in advance of the entrance to a. turnout track and also in a section of the turnout track.

Other characteristic advantages and features of the invention will be in part apparent and in part brought out as the description of the invention progresses.

In describing the invention references will be made to the accompanying drawing showing in a diagrammatic form and in no manner in a limiting sense one form which the invention may assume. In the drawing:

Fig. 1 is a diagrammatic illustration of the trackway apparatus in accordance with this invention.

Fig. 2 is a diagrammatic illustration of the car carried apparatus in accordance with this invention.

Fig. 3 is a diagrammatic illustration of the codes which can be employed in connection with this invention.

For the purpose of further simplifying the illustration and facilitating in the explanation thereof, various parts and circuits constituting the embodiment of the invention have been shown diagrammatically and certain conventional illustrations have been employed, the drawing having been made with the idea of making clear the purposes and principles of the invention together with the mode of operation rather than with the idea of showing the construction and arrangement of parts that would most advantageously be employed in practice.

The various relays and their contacts are illus- 5 trated in a conventional manner and symbols are employed to indicate connections to terminals of batteries and other suitable sources of electric current supply instead of showing all the wiring connections to such terminals. Symbols l") and are employed to indicate the positive and negative terminals respectively of suitable batteries or other sources of electric energy and those terminals with which these symbols are used are presumed to have current flowing from h the positive terminal designated to the negative terminal designated Symbols employed with any one circuit are considered to designate a single source of energy in this embodiment of the present invention but as many sources. may be provided as found necessary or expedient in the practice of the invention.

Trackway apparatus.--Referring to Fig. 1 there is here shown a track layout comprising a main track I and a turnout track 2 connected to the main track by a switch TS which is operated by a switch machine SM that may be of any suitable type.

The rails l are divided into blocks in the usual manner by insulating joints 3, block A with the adjacent ends of blocks B and C being shown. In the particular arrangement shown section D of the turnout track 2 enters the main track at section A and is defined by insulated joints 4, andthe switch parts are bonded in the usual manner to provide fouling point protection.

The present invention has been shown applied to a signal system employing semaphore signals, signal S being a track circuit controlled signal and signal S governing traffic into the turnout track being a lever controlled signal always responsive to the position of its controlling lever and never traffic controlled.

Although a direct current track circuit for blocks A and D, with the usual track battery T and direct current track relay 'I connected to rails I as shown in Fig. 1 has beenused in connection with this invention an alternating current track circuit may be employed if desired.

constituting a further part of the trackway apparatus, and of the same general type as in the W. D. Hailes Patent No. 1,914,330, dated June 13, 1933, is a code motor M having field windings 5 and 6 and controlled by a hand switch HS for 55 connecting the motor to a source of alternating current the terminals of which being indicated by the letters E and F.

Operated by motor M and preferably by being mounted on the same shaft is code wheel I designed as shown in the drawing to operate contact 8 for making and breaking a code applying circuit to the primary coil of transformer T.

Control lever CL is provided for controlling energy to the primary of transformer T and is operable to the right for sending the code indicating stop and to the left for sending the code indicating back up.

One side of the secondary of transformer T is connected through a front contact 9 of the track relay T to the extremity of code wire CW adjacent to section A of the trackway and the other side of the secondary of transformer T is connected to the other extremity of code wire CW. A circuit, which includes code wire CW and a contact [0 of signal S in its clear position, is provided to energize code wire CW when track relay T is deenergized. Thus code wire CW employed as shown in Fig. 1, extends the length of trackway under control, a distance equal to the length of code wire CW In practicing the invention code wire CW should extend a greater distance from section A than the distance required by the longest train to clear section A and section A of the trackway should extend only a short distance to the left of the switch TS.

In connection with the code to be placed on the code wire, the code wheel I is shown with one tooth constituting half of its circumference, whereby if code motor M is operated at a rate of 40 revolutions per minute and lever CL positioned to the left, energy will be supplied and removed from the primary of transformer T 40 times per minute.

Before describing the car-carried apparatus which automatically responds to coded and steady-on energy in the code wires the operation of the apparatus in Fig. 1 will be described more in detail.

When hand switch HS is closed, code motor M is started through a circuit from one terminal E of the alternating current source, hand switch HS, field coil 5 and phase shifting means 5 in series, an field coil 6, of motor M, in multiple, t0 the other terminal F of the source of current.

If the control lever CL is moved to its left hand position for sending out a back up code, energy of 40 impulses per minute is applied to the primary of transformer T through a circuit which includes code contact finger 8. If control lever CL is moved to its right hand position for sending out a stop code, steady-on energy is applied to the primary of transformer T through a circuit obvious from the drawing.

Car-carried apparatua-Referring to Fig. the vehicle carrying the train control apparatus is represented by wheels and axles ll, receivers R and R being located in advance of the front and rear axles of the vehicle midway between the rails l and in inductive relation with code wire CW, the two receivers being sufficiently separated to bridge any dead section in the code wire CW.

Receivers R and R are connected in series to the primary coil of a transformer T through a circuit tuned to the frequency of the alternating current employed and which includes a condenser l2. The secondary of transformer T is connected to the input side of an amplifier AMP which is constructed in accordance with recog nized principles to amplify the current induced in receivers R and R The output side of amplifier AMP is connected to a coding primary relay CPR having contacts l3 and M which contacts control the energizing circuits for decoding relays CR and CR With the receiving apparatus described above it is clear that relay CPR follows the application and removal of current to and from the code wire CW so as to pick up and release depending upon whether train control current is on or off the code wire. Thus, with selected codes such as back up and stop, shown in Fig. 3, relay CPR respectively oscillates, and stays steady up.

Contact finger I3 of relay CPR which follows the code, operates to place energy when picked up on one-half of the primary coil of a transformer T and to likewise energize the other half of the primary coil of transformer T in a reverse direction when released there being a condenser [5 connected across the primary of transformer T This operation results in the transfer of energy to the secondary of transformer 'I on each make and each break of contact finger l3 of relay CPR to thereby energize a pick up circuit for relay CR with uni-directional current, which circuit is through one or the other rectifiers RECT and RECT wire I6, coil of relay CR wire 11, back to the mid-tap of the secondary of transformer T Relay CR will of course pick up only if supplied with energy from the secondary of transformer T and thus is up only on the 40 code,

and is not picked up with the stop or steady current code. The other decoding relay CR energized through back point of contact I4, is designed to be slow to release so that when once picked up, it will stay up when relay CPR is deenergized as during the on periods in the 40 code.

The relays CR and CR in combination operate to control the signal indications BU and ST which indicate back up and stop to the engineer. When the 40 cycle code is present in the code wire relays CR and CR will pick up and stay up to display the BU indication through an obvious circuit. When steady-on energy is present in the code wire, relay CPR will pick up and remain picked up, and relays CR and CR will both be deenergized thus closing a circuit to the lamp of indicator ST. With no current in the code wire it is obvious that the lamps in both indicators BU and ST will be extinguished, as the BU indication circuit is open at contact [9 of relay CR down, and the ST indication circuit is open at contact 20 of relay CR Operation In order to facilitate a complete understanding of this invention the operation of the same will be taken up in some little detail in the following.

Referring again to Fig. 1 let us assume a long train such as train V shown in section C of the energy will be applied to code wire CW through a circuit which includes the secondary of transformer T and front contact 9 of track relay T thus causing a stop indication to be displayed in the cab of train V, at the earliest possible time after the train has cleared section A.

After switch TS and signal S have been positioned for a move into the turnout track, 1. e., signal S at clear, control lever CL is moved to its left hand position. The 40 cycle code will then be applied to code wire CW thus causing a back up indication to be displayed in the cab of train V. After train V enters section A track relay T will drop but the circuit to code wire CW will be maintained through a shunt path comprising code wire CW and contact i0 controlled by signal S Thus, means of communication for transmitting stop? and .back up controls have been established with train V and such communication means will be maintained until receivers R and R of train V clear the code wire CW in section D of the turnout track.

The above rather specific description of one form which applicant's invention can assume has been given solely by way of illustration and is not intended in any manner whatsoever in a limiting sense. In practicing the invention the trackway under control could be extended to include a plurality of turnout tracks and switches, with a code wire in each track properly interlocked with the code wire along side the main track.

Obviously the invention can assume various different forms and is susceptible of numerous modifications and all such forms and modifications are intended to be covered by this application as come within the scope of the appended claims.

What I claim is:

1. In a train control system, in combination, a stretch of main track including a turnout, an insulated track block including the turnout and ending just beyond the point where the turnout joins the main track, a track circuit including a track relay in the block, a circuit adjacent and paralleling the main track and including a contact of the track relay, wayside means for placing control energy on the.circuit, and vehicle carried means responsive to the control energy.

2. In a coded train control system, in combination, a stretch of main track including a turnout, an insulated track block including the turnout and ending just beyond the point where the turnout joins the main track, a track circuit including a track relay in the block, a circuit adjacent and paralleling the main track and including a front contract of the track relay, wayside means for placing coded control energy on the circuit, and vehicle carried means responsive to the control energy.

3. In a coded train control system, in combination, a main track, a turnout track, a switch for connecting the turnout track to the main track, a track circuit including the switch and short sections of the main and turnout tracks adjacent the switch, a conductor adjacent, and paralleling, the main track and extending from the switch to a predetermined point inadvance of the entrance to the turnout track, means selectively energizing the conductor with currents of distinctive character when the track circuit is unoccupied, to send out stop and back up codes, and car carried receiving apparatus for responding to the currents of different character to display stop and back up indications informing the engineer when his train has cleared the track circuit.

4. In a coded train control system, in combination, a main track, a turnout track, a switch for connecting the turnout track to the main track, a track circuit including the switch and short sections of the main and turnout tracks adjacent the switch, conductive means associated with a relatively long section of the main track in advance of the entrance to the turnout track, manual means for selectively applying to said conductive means currents of distinctive character in accordance with the future movements of a train passing over the switch section onto the section in advance of the turnout track, car carried indicating apparatus distinctively responsive to the currents of distinctive character in said conductive means to set up inthe car various indications, and means whereby the first indication will be displayed immediately after the rear end of said train has passed out of the track circuit.

WADE H. REICHARD. 

